Doctors prescribe their patients medicines to keep them well, but ineffective communication can lead to poor medication adherence, according to a study described in the journal JAMA Internal Medicine, formerly known as the Archives of Internal Medicine.

Researchers at the University of California, San Francisco (UCSF), San Francisco General Hospital and Trauma Center (SFGH), and the Kaiser Permanente Division of Research asked 9,377 patients through a questionnaire to rate how well their physicians communicated with them. Patient medication adherence was determined by measuring delays in refilling prescriptions. The researchers found that patients who gave their doctors poor marks in communicating were less likely to adhere to their medications.

“Communication matters,” lead author Neda Ratanawongsa, MD, MPH, an assistant professor in the UCSF Department of Medicine and the UCSF Center for Vulnerable Populations at SFGH, said in a news release. “Thirty percent of people [in the study] were not necessarily taking their medications the way their doctors thought they were. Rates for non-adherence were 4 to 6 percent lower for patients who felt their doctors listened to them, involved them in decisions and gained their trust. By supporting doctors in developing meaningful relationships with their patients, we could help patients take better care of themselves.”

The study, which is part of the Diabetes Study of Northern California (DISTANCE), suggests preparing doctors to be better communicators may help improve medication adherence and ultimately health outcomes.

Andrew Karter, PhD, a senior research scientist with the Kaiser Permanente Division of Research and the principal investigator of DISTANCE, also said they found “medication adherence is better if the physician has established a trusting relationship with the patient and prioritizes the quality of communication.”